"A colleague swears she has photos of Janet Reno rocking a tool belt."

Upstairs at the Roots & Branches School, volunteers spent a weekend day building a sensory room, its walls hung with scrub brushes, ropes and sponges — tactile delights for the elementary-aged students. Downstairs, crews painted silhouettes of athletes around the gym, a surprise for the children when they return to the charter school in West Baltimore after the holiday weekend.

The two dozen volunteers on Saturday answered the national call for service around the birthday of Martin Luther King Jr., the slain civil rights leader who once requested that his eulogy mention "Martin Luther King Jr. tried to give his life serving others."

President Ronald Reagan signed the legislation that made Martin Luther King Day a federal holiday in 1983, and a decade later President Bill Clinton backed the bill that made it a day of service. Then President Barack Obama raised the mission to new heights.

On the eve of his 2009 inauguration, Obama urged Americans to honor the civil rights leader by volunteering in their communities — he helped paint an emergency homeless shelter for youths in Washington — and the number of service projects jumped.

As families across Maryland and the nation fan out to serve in the final day of service under a president who has been its champion, volunteers and organizers are confident the tradition will continue to grow.

"Since President Obama, I have actually seen more people wanting to volunteer," said Kamala Stevenson, a therapist from Glen Burnie who strung lights in the sensory room at Roots & Branches. "I would hope that things won't change."

Service on Martin Luther King Jr. Day has increased nearly 9 percent from 2014 through 2016, the most recent years available, according to Points of Light, the nonprofit founded by President George H.W. Bush to promote volunteerism.

"The national service and volunteer movement is strong in America," said Malikah Berry, the senior vice president for programs.

CAPTION

Baltimore residents have an opportunity to listen to and speak out about acting police commissioner Darryl De Sousa at the Baltimore City Council hearing. (Algerina Perna, Baltimore Sun video)

Baltimore residents have an opportunity to listen to and speak out about acting police commissioner Darryl De Sousa at the Baltimore City Council hearing. (Algerina Perna, Baltimore Sun video)

Today in Baltimore, families have signed up to serve casserole at a Fells Point homeless shelter, clear overgrowth in Johnston Square and shovel compost at Charm City Farms.

Nationwide, federal officials say, more than 200,000 people will volunteer on projects across all 50 states.

"We've been lucky that all administrations have supported service and volunteering, as well as the MLK Day of Service, and I hope the new administration will continue to do so," said Samantha Jo Warfield, spokeswoman for the Corporation for National and Community Service.

Obama has planted a school garden, served lunch in a soup kitchen and painted cafeteria murals. President George W. Bush shelved books at a D.C. library. Vice President Joe Biden hung drywall in a Habitat for Humanity home.

Warfield credited Obama with igniting participation around his 2009 inauguration.

"That exploded after the president took office," she said. The King holiday fell a day before that inauguration. "We turned them all into one big, huge national day of service."

Obama was scheduled to volunteer Monday afternoon at a Jobs Have Priority family shelter in Washington. It was unclear whether or where President-elect Donald J. Trump would participate. The Trump transition team did not respond to a request for information.

More than 350 volunteers are expected to gather in East Baltimore Monday morning for work planned by The 6th Branch, a nonprofit composed of military veterans. Crews plan to clear remnants from demolished, vacant buildings to prepare for a football field for St. Frances Academy high school. Without a field of their own, the Panthers have practiced at four scattered sites.

On Saturday, the national veterans group Mission Continues delighted Principal Anne Rossi with its work to dress up the Roots & Branches gym.

The children were in for a surprise, Rossi said.

"It's going to be a little like Christmas," she said. "The elves have been in here."

King urged such service in February 1968 with his "Drum Major Instinct" sermon.

"Everybody can be great, because everybody can serve," he said. "You don't have to have a college degree to serve. You don't have to make your subject and your verb agree to serve. … You only need a heart full of grace."

Congress wrote that message into law in 1994 with the King Holiday and Service Act of 1994.

"It should be a day on, not a day off. That was our slogan," said former Sen. Harris Wofford of Pennsylvania, who sponsored the legislation with Rep. John Lewis of Georgia.

Lewis, an intimate of King's, helped organize the 1963 March on Washington and the 1965 March on Montgomery. He suffered a fractured skull when he was clubbed by Alabama state troopers at the Edmund Pettus Bridge in Selma, Ala., in what became known as "Bloody Sunday."

Lewis and Trump sparred over the weekend.

Lewis told NBC's Meet the Press on Friday that he didn't consider Trump to be a "legitimate president" in the wake of allegations of Russian meddling in the election.

Trump tweeted Saturday that Lewis was "All talk, talk, talk — no action or results," and should focus instead on "Helping his district, which is in horrible shape and falling apart (not to mention crime infested)."

Wofford, a lawyer, counseled King.

"With Martin Luther King, we have the chance of doing something big, and on the day that would signal efforts of big action and big numbers," he said.

Still, he envisioned 1994 unleashing a groundswell of volunteerism.

"I'm not satisfied," he said. "There are places like Philadelphia that have shown how big you can get it. How do you do it in Baltimore, at this moment, I don't know. But it's an idea that will be there for those who want to pick it up."